【摘要】 <正> 一、前言江苏宁镇山脉是我国发现笔石最早的地区之一(Frech,1912),也是我国下古生界研究程度较高的地区之一。近年来,在昆山及苏北沿海地区的奥陶、志留系中陆续发现笔石、牙形刺等化石(葛梅钰等,1982;葛梅钰,1984;段金英,1985;丁连生,1987),证明了这些地区奥陶系、志留系的存在,同时,也表明这些地区在奥陶纪、志留纪应属于扬子区或扬子海的边缘地区。上更多还原

【Abstract】 This paper makes the first description of the Late Ordovician graptolites from Shanghai. The material dealt with was collected from the boring hole mudstone corresponding to part of the Upper Ordovician Wufeng Formation.The strata of the boring hole sections provided by Xu Bao-tong are the same as the Ordovician strata of the Nanjing and Yichang areas in biostratigraphic sequence and lithological character. Thus, this paper further suggests and demonstrates that the Shanghai area belongs to the eastern margin of the Central China Region as Kunshan of Jangsu and Jing Shan Ling of Yu Hong of Zhejiang.Description of new species Diplograptus acutifolius sp. nov.(P1.Ⅰ, fig. 8)Rhabdosome 10mm in length, tapering in th proximal part and acutely rounded at proximal end, gradually widening upwards from 0.5mm across the first pair of thecal aperture to 0.7mm,1.3mm and 1.5mm at proximal 2.5mm, 5mm and 7.5mm respectively, and to a maximum of 1.7mm at distal end.Sicula unclear, but with its widened apertural part 0.15mm in width and virgella sturdy, about 0.25mm in length. Proximal 4 pair thecae of climacograptid type; all others of orthograptid type.Thecae 1.6mm in length, 0.4mm in width, inclined at 30°, and overlapping one half, with 7.5—8.0 in proximal 5mm, 12.5—13.0 in proximal 10mm.更多还原